Process of preserving wood



UNITED STATES PATENT OFFICE.

JOSEPH A. SEWALL, on DENVER,- cononAno.

PROCESS OF PRESERVING WOOD.

SPECIFICATION forming part of Letters Patent No. 374,208, dated December 6, 1887.

Application filed July 23,,1887. Serial No. 245,083. (No specimens.)

T0 (ZZZ whom it may concern:

Be it known that I, Josnrrr A. SEWALL, a citizen of the United States, residing at Don ver, in the county of Arapahoe and State of Colorado, have invented certain new and use ful Improvements in Processes of Preserving Wood from Decay; and I do declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

The object of my invention is to preserve wood from decay.

To carry'my invention into effect-,1 place the wood to be treated in a vacuum-tank, from which I then exhaust the air, after which I introduce asaturated solution of boracic acid, which is allowed to remain in contact with the wood until the same is thoroughly saturated with the solution, which should occupy about two hours. The surplus acid is then removed from the tank and a saturated solution of lime (calcic hydrate) in a sufficient quantity to cover the wood is placed in the tank and is allowed to remain about two hours, until the lime has united with the borac'ic acid and a coating of calcic borate extending a short distance into the wood has been formed, which coating prevents any action of water on the boracic acid,which latter is the preserving agent. The solutions above mentioned should be cold.

Having now fully described my invention, what I claim as new, and desire to secure by Letters Patent, isr The herein-described process of preserving wood, which consists of thoroughly impregnating the wood with boracic acid and subsequently treating it to a bath of calcic hydrate, substantially as described and set forth.

In testimony whereof I affix my signature in presence of two witnesses.

JOSEPH A. SEWALL.

Witnesses:

H. W. ARNOLD, B. L. PoLLooK. 

